200Apk, 270V bus, 40 uS ON@200BPS, 60VA out of the wall. Sparks are ~6" long

The interrupter lives in a separate box, and is coupled into the driver with coaxial cable. This works OK, though there are still some noise issues that cause the pulsewidth to fluctuate.

Schematic:

Get the Eagle board files[here] if you want to make one...its not quite perfectly reliable yet (in particular, it probably needs a optoisolated interrupter), but it does 6 or 7 inches at 100W fine.
If you're incredibly lazy, the DigiKey order for the most of the components (not the 40N60's), is [here]

and these http://www.reichelt.de/IGBTs/IRG-4PC-50UD/3/index.html?;ACTION=3;LA=446;ARTICLE=90433;GROUPID=2888;artnr=IRG+4PC+50UD;SID=10UGHZ2n8AAAIAAGJhoQ0e42f72f9a86e3468ade09d442257d501 sorry i dont want to wait so long for the igbts from china :-) Im germanand what current transformer do you use (how many windings)??

You want to get the FGH60N60SMD's from Arrow (which is most certainly not in China).I use this CT http://www.digikey.com/scripts/DKSearch/dksus.dll?Detail&itemSeq=119739217&uq=634842613340537351 from Digikey.